import { mxRootChange } from "../model/GraphModel";
import { mxConstants } from "../util/mxConstants";
import { mxCodecRegistry } from "./mxCodecRegistry";
import { mxObjectCodec } from "./mxObjectCodec";

/**
 * Copyright (c) 2006-2015, JGraph Ltd
 * Copyright (c) 2006-2015, Gaudenz Alder
 */
mxCodecRegistry.register(function () {
	/**
	 * Class: mxRootChangeCodec
	 *
	 * Codec for <mxRootChange>s. This class is created and registered
	 * dynamically at load time and used implicitly via <mxCodec> and
	 * the <mxCodecRegistry>.
	 *
	 * Transient Fields:
	 *
	 * - model
	 * - previous
	 * - root
	 */
	var codec = new mxObjectCodec(new mxRootChange(null, null),
		['model', 'previous', 'root']);

	/**
	 * Function: onEncode
	 *
	 * Encodes the child recursively.
	 */
	codec.afterEncode = function (enc, obj, node) {
		enc.encodeCell(obj.root, node);

		return node;
	};

	/**
	 * Function: beforeDecode
	 *
	 * Decodes the optional children as cells
	 * using the respective decoder.
	 */
	codec.beforeDecode = function (dec, node, obj) {
		if (node.firstChild != null &&
			node.firstChild.nodeType == mxConstants.NODETYPE_ELEMENT) {
			// Makes sure the original node isn't modified
			node = node.cloneNode(true);

			var tmp = node.firstChild;
			obj.root = dec.decodeCell(tmp, false);

			var tmp2 = tmp.nextSibling;
			tmp.parentNode.removeChild(tmp);
			tmp = tmp2;

			while (tmp != null) {
				tmp2 = tmp.nextSibling;
				dec.decodeCell(tmp);
				tmp.parentNode.removeChild(tmp);
				tmp = tmp2;
			}
		}

		return node;
	};

	/**
	 * Function: afterDecode
	 *
	 * Restores the state by assigning the previous value.
	 */
	codec.afterDecode = function (dec, node, obj) {
		obj.previous = obj.root;

		return obj;
	};

	// Returns the codec into the registry
	return codec;

}());
